Recovery of lithium from bitterns



J. R. NELLI ETAL 3,537,813 `RECOVERY OF LITHIUM FROM BITTERNSISSheets-Sheet l Raimi m. E Ss us5,

` Filed April 25. 1968 11.02.1970 1R. NELL. Em 3,537,813

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1on1 122B 0PM 122 'raul 1010 United States Patent O 3,537,813 RECOVERYOF LITHIUM FROM BITTERNS Joseph R. Nelli and Theodore E. Arthur, Jr.,Gastonia,

N.C., assignors to Lithium Corporation of America, New York, N.Y., acorporation of Delaware Continuation-impart of application Ser. No.570,192,

Aug. 4, 1966. This application Apr. 25, 1968, Ser.

Int. Cl. C01d 11/02 U.S. Cl. 23--89 17 Claims ABSTRACT OF THEyDISCLOSURE A process for recovering certain mineral, especiallylithium, values from liquids obtained from brines or sea water, after-removing the major content of sodium chloride and reducing the contentof other salts in said brines or sea water. A metal halide which isreactive with lithium to form a lithium-containing compound,particularly ferric chloride, is added to the liquid, together with anacid, such as hydrochloric acid, to inhibit hydrolysis of the metalhalide, and the lithium values are recovered by extraction with awater-insoluble organic solvent, phase separation, and washing of saidseparated organic solvent extract phase with Water.

CROSS-REFERENCE TO RELATED DISCLOSURE This application is acontinuation-impart of application Ser. No. 570,192, led Aug. 4, 1966,now abandoned.

BACKGROUND OF THE INVENTION Field of the invention The present inventionrelates to a process for recovering certain residual mineral values,particularly lithium, from Waste liquids or bitterns resulting from theextraction of various salts from brine or sea water.

Description of the prior art It is Well recognized that the Wasteliquids resulting from the processing of brines or sea water containirnportant mineral values. Among these are lithium salts, particularlylithium chloride, which is present in the waste liquid in small, butcommercially significant, quantities along with various percentages ofother salts principally including those of magnesium, sodium andpotassium. Considerable research and eiort have been directed toward thedevelopment of processes for recovering the lithium values from suchWaste liquid. While a number of processes have evolved from work in thisarea, generally speaking, they are unsatisfactory due to theircomplexity and the excessive costs involved in the ultimate recovery ofthe desired values. As a consequence, there are essentially no largecommercial operations in use wherein the recovery of such values iscarried out separately or as a part of an overall process for recoveringmineral values generally from brines or sea water. The present inventionprovides a simple, inexpensive procedure for recovering lithium valuesfrom waste liquids of the type mentioned.

SUMMARY OF THE INVENTION In accordance with the present invention, ithas been discovered that a high percentage of the lithium valuescontained in waste liquids or bitterns resulting from the processing ofbrines or sea water can be recovered by adding a metallic, andespecially an iron, salt to the liquid under conditions to inhibithydrolyzation of the salt, whereby the salt reacts with the lithiumsalts, e.g. lithium chloride, present in the liquid to form a compoundwhich then can be extracted from the liquid with a suitable 3,537,813Patented Nov. 3, 1970 ICC organic solvent. The lithium is then separatedfrom the compound and the metallic salt and the organic solvent isrecycled in the process. The extraction of the cornpound formed by thereaction of the metallic salt With the lithium is carried out with anorganic solvent which is essentially insoluble, or diicultly soluble, inwater. Reextraction of the compound from the organic solvent isachieved`\ with ordinary tap water. The reaction involving the lithiumpresent in the Waste liquid or bitterns takes place substantiallyindependently of other mineral values present. While the process of thepresent invention is uniquely suitable for the recovery of lithiumvalues, it can be used to advantage in recovering or extracting and/ orseparating other mineral values in Waste liquids or bitterns. Thus,other alkali metal salts (other than sodium), and other metal salts, forexample, magnesiurn salts, commonly present in such liquids, can beBRIEF DESCRIPTION OF THE DRAWING The accompanying drawing FIG. 1 is adiagrammatic or schematic form of equipment arrangement for carrying outthe process of the present invention.

FIG. 2 represents an arrangement similar to that of FIG. l but includesthereon references to compositions of the starting bitterns and materialbalances in the compositions of at the various stages of the process ina typical illustrative example in carrying out the extractions, Washesand stripping operations in multiple stages.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The metallic salts havingutility in the practice of the present invention are characterized inthat they are capable, in solution, of forming a stable compound withlithium, and/or magnesium, if such be the case, which can be extractedWith a suitable organic solvent and then recovered, as by simpleextraction, from the solvent. As indicated, the metallic salt is addedto the Waste liquid or bitterns under conditions such that the salt willnot be hydrolyzed to any appreciable extent. To this end, the metallicsalt advantageously, and further, is characterized in that it is capableof forming, with an acid, a dissociable acid salt or complex which, insolution, resists hydrolyzation but readily undergoes a replacementreaction with, for instance, a lithium salt to yield the desiredextractable compound.

While there are a number of metallic salts having properties whichsatisfy the foregoing criteria, the objectives of the present inventionare most advantageously met by utilizing metal halides, particularly thechlorides and bromides of ferrie iron, cobalt and nickel. Of this group,ferrie chloride, especially in a hydrated form such as ferrie chloridehexahydrate, is preferred and the dissociable acid salt or complex whichis formed is soluble lithium tetrahaloferrate. The metal halide can beadded to the waste liquid or bitterns as an acid solution or can beadded to a suitably acidied waste liquid or bitterns. The concentrationof the metal halide solutions employed in the practice of the presentinvention is somewhat variable. In utilizing ferric chloride, forexample, as the me- 4 tallic salt, good results can be attained withsolutions comprising, by Weight, from about '30 to 50% ferrie chloride,with particularly satisfactory results being obtained with solutions inwhich the weight percent of ferric chloride ranges from about 38 to 45%,for instance, a 42 Baume solution which contains about 40% ferriechloride.

The process of the present invention can be carried out in both chlorideand bromide systems. The acid employcd, therefore, should be one whichis compatible with such a system. Further, in this same connection, theacid used in the process advantageously is one that is capable offorming an acid salt or complex with the metallic salt which, insolution, will not only substantially prevent hydrolyzation of themetallic salt but will dissociate to provide an anion for reacting withthe desired metal cation values present in the waste liquid or bitterns.In a chloride system, utilizing ferrie chloride as the metal halide torecover lithium values, for example from the system, the preferred acidsare chlorinecontaining acids such as hydrochloric or perchloric acid. Insuch a system, the hydrochloric acid or perchloric acid desirably isemployed in the form of aqueous solutions of strength of from about to30%, usually about Sulfuric acid can also be employed but it isparticularly preferred to use hydrochloric acid.

The quantity of the metallic salt that is added to the Waste liquid orbitterns can vary within appreciable limits. Thus, by way ofillustration, in recovering lithium values from a chloride systemutilizing ferrie chloride as the metallic salt, the generally optimumobjectives of the invention are attained when the ferrie chloride isintroduced in an amount sufiicient to provide a ferrie-tolithiumgram-ion ratio of the order of from about 0.5 :1 to about 1.5:1,especially desirably a gram-ion ratio of about 1:1.

The acid, whether added as part of the metallic salt solution orseparately, should be present in the waste liquid or bitterns in anamount such that the acid concentration is suciently high to preventhydrolysis of the metallic salt. To this end, the acid should be used inan amount sufficient to provide an acid concentration in the wasteliquid or bitterns in the range of from about 0.*02 N to 0.3 N, usually0.04 N to 0.1 N.

The organic solvents employed in the process of the present inventionfor extracting the desired compound formed in the waste liquid orbitterns, apart from having good extraction properties with respect tosaid compound, are characterized in that they are insoluble, ordifcultly soluble, in water, and thus are readily separable from theaqueous phase of the solutions by decantation or other such conventionalseparation techniques. Of a variety of solvents satisfying thesecriteria, certain oxygen-containing solvents are particularly suitablefor the purposes of this invention. Exemplary of such solvents areesters such as n-butyl acetate, ethyl acetate, amyl acetate andisopentyl acetate; ketones exemplified by distilled cyclohexanone,diisobutyl ketone and isobutyl methyl ketone; ethers such as diisopropylethers; l-ethoxybutane and 1- ethoxyhexane; alcohols such as 3-methylpentanol and 2-hexanol; and the like, and compatible mixtures thereof.Of this group, diisobutyl ketone is especially preferred due to its lowsolubility in water, its general availability, its good extractionproperties, and its good chemical stability.

It is especially desirable to use, in conjunction with theaforementioned solvents, certain neutral or acidic phosphorus esterssuch as are described below, and particularly satisfactory is tributylphosphate. Such phosphorus esters are used in minor proportions in themixture of solvents. They tend to enhance the extraction of the desiredcompound and they tend to reduce the possibility of formation ofundesirable emulsion conditions. In general, such phosphorus esters,where used, will usually constitute from 15 to 25%, by volume, of thetotal solvent mixture. An illustrative, and highly desir- 4 able,solvent mixture is about diisobutyl ketone and about 20% tributylphosphate.

The quantity of organic solvent utilized in the extraction step of theprocess can vary within appreciable limits. From the standpoint ofpractical considerations, however, it is desirable to employ only somuch of the solvent as is necessary to effect extraction of the compoundresulting from the reaction of the anion furnished by the dissociablemetallic salt-acid salt or complex with the metal cation value, orvalues, present in the waste liquid or bitterns. Generally speaking, theobjectives of this invention can be attained at the extraction step ofthe process with organic solvent-to-aqueous solution volume ratiosranging from about 0.5:1 to about 3:1, especially desirably with a ratioof about 1 to 2 of the organic solvent to 1 of the aqueous solution. Atthe wash step, following extraction with the organic solvent, theorganic solvent-to-aqueous ratios advantageously should range from about8:1 to about 15:1, preferably from about 10 or 11 volumes of the organicsolvent to 1 of aqueous solution. The higher organic solvent-to-aqueousratio employed at this step in the process tends to limit the drive ofthe desired metal value-containing compound into the aqueous phase, Atthe strip step of the process, on the other hand, recovery of thedesired metal values is favored by organic solvent-to-aqueous ratiossubstantially lower than those utilized at the wash step. Generallyspeaking, organic solvent-to-aqueous ratios at this step will range fromabout 3:1 to about 10:1, usually about 3 to 7 volumes of the solvent to1 of the aqueous solution.

Referring, now, to FIG. 1 of the accompanying drawings, in which thereis illustrated in diagrammatic or schematic form an arrangement forcarrying out the process of the present invention for the recovery oflithium values from bitterns by a continuous countercurrent single stageor multi-stage mixer-settler operation, at extraction step 1, a bitternssolution, to which an aqueous ferrie chloride-hydrochloric acid solutionhas been added, forming soluble lithium tetrahaloferrate is contactedwith an organic solvent stream. The adjusted bitterns solution andsolvent are thoroughly mixed, and phase separation is then allowed totake place. The aqueous rainate phase from step 1 is discarded and theorganic phase is passed to a wash step 2 where it is mixed with a streamof fresh water. Following phase separation at step 2, the washed extractis passed to a strip step 3. Here the washed extract is contacted withanother stream of water. The solvent-rich stripped extract from step 3is recycled to step 1 while the strip liquor is passed to a secondextraction step 4. Prior to entering step 4, the chloride ion content ofthe strip liquor from step 3 is adjusted by the addition thereto of achlorine-containing salt such, for example, as sodium chloride orpotassium chloride. The quantity of the chlorine-containing salt addedat this step in the process should be suicient to provide a chloride ionconcentration in the strip liquor of at least 2 M, and preferablyhigher. The increased chloride ion concentration in the strip liquortends to drive the ferrie iron into the organic phase resulting from theaddition, at step 4, of a solvent to the strip liquor. The solvent addedat this step advantageously should favor extraction of the ferrie ironpresent in the strip liquor to the exclusion of the lithium valuescontained therein. Exemplary of a solvent having good selectivity as-well as extraction capabilities for this purpose is a mixed solventcomprising a combination of a neutral phosphorus ester, an acidicphosphorus ester and a diluent, such that the physical and chemicalproperties of the individual components of the combination complementeach other. The neutral phosphorus esters employed in the combinationcan be characterized in that the substituents on the phosphoryl group,P20, may be alkoxy, RO, a combination of alkoxy and alkyl, or alkyl,wherein the alkyl substituent or substituents, may be represented by thegeneral formula CnH2n+1. Generally speaking, the order of increasingextraction power of the neutral phosphorus ester, based on substitutionof the phosphoryl group, will be phosphate, phosphonate, phosphinate andphosphine oxide. The acid phosphorus ester component used in the tiondoes not increase lithium value extraction but does increase magnesiumextraction; and (2) increasing the acid concentration decreases theextraction of both lithium and magnesium values but produces lowermagnesium-to-lithium value ratios.

mixed solvent can be characterized in that the substituents 5 Theprocess of the present invention, in its optimum on the divalentphosphino group, :POOH, thereof may be aspects, enables the recovery ofgreater than 80% of the dialkoxy or dialkyl, while the substituents onthe monolithium values from waste liquids or bittems having a valentphosphonon group, :PO(OH)2, where such is the magnesium-to-lithium ratioof about 100:1. The ecocase, may be monoalkoxy or monoalkyl. The diluent10 nomics of the process are extremely good both from utilized in themixed solvent most advantageously is a the standpoint of the relativelyfew processing steps non-polar aromatic hydrocarbon exemplitied bybenzene, involved and in view of the fact that both the metallictoluene, and xylene, or commercially available aromatic salt and thesolvent utilized can be readily recovered for diluents such as thosesold under the trade designations recycle through the process. AmscoSolv D (American Oil Co.) and Solvesso 100 15 In FIG. 2, the materialbalances are shown, in the case (Esso). An illustrative example vof amixed solvent havof an illustrative example, in relation to the varioussteps ing the properties desired is one containing tri-n-butyl of theprocess. The following abbreviations apply: g.p.m. phosphate anddi(2ethyl hexyl)phosphoric acid, in a is gallons per minute; -IBK isdiisobutyl ketone; TBP is mole ratio of about 1:1, with benzene as thediluent. tributyl phosphate; EHPA is di-Z-ethylhexyl phosphoric `Thesolvent extract from step 4 is passed to a strip 20 acid; and O/A isorganic to aqueous volume ratio. step 5 where it is contacted with astream of water. The The following examples are illustrative of thepractice stripped solvent from this step is recycled to step 4 and ofthe present invention. While the examples primarily the strip liquor,containing the recovered ferrie chloride, involve a mulitstagecontinuous countercurrent mixeris recycled through the process. Theaqueous product settler, batch type operation, it should be understood,as from step 4 contains the desired lithium values in the 25 indicated,hereinabove, that a distinctly major percentage form of lithiumchloride. The aqueous solution is of the desired lithium values can beextracted in a single evaporated to effect precipitation of thechloride-containstage. ing salt added to the strip liquor obtained fromstep 3. Following separation of the precipitated salt from the EXAMPLE Iaqueous product, which salt may be recycled to step 4, EXtfaCtiOIlStep-3,000 ITS- 0f a Synthetic bittems (a the resulting solution may beevaporated to obtain saturated aqueous chloride solution containingabout anhydrous lithium chloride, or the lithium values present 0076%Lt, 780% Mg, 022% N3, 020% K and 20% therein can be recovered bychemical means as by addi- 30K) Were adjusted With 127-6 m15- Of 42 B-FeCla tion of sodium carbonate to effect precipitation of the SOlUtOnand 10 InlS- 0f 25% HC1 Solution, thefeblr formlithium as lithiumcarbonate. ing soluble lithium tetrahaloferrate. This adjusted bittemsBy far the major proportion of the lithium values is had a gin-On latO0f Li t0 Fe 0f about 1 t0 1, and extracted at step 1 of the process,but, from an economic a HC1 Concentration 0f abOut 0.07% t0 preventhystandpoint, in mulitple stages. The raffinate from step 1 drolysis ofthe FeCl3. In a batch simulation of a sevenmay be discarded or treated,if desired, to recover lithium stage continuous, countercurrentmixer-settler operation, and other mineral values therefrom. In thoseinstances 300 mls. of adjusted bitterns were contacted with 200 mls.where lithium and magnesium are present in the bittems of diisobutylketone (DIBK). 9, 7, 51/2 and 4 mls. of 42 and the magnesium mayinterfere With the extraction B. FeCl3 solution were added to theaqueous Phases of the lithium values, it is possible, in accordance withleaving stages 7, 6, 5 and 4, respectively. the practice of thisinvention, to control the extent of Wash step-In a batch simulation of afour-stage conmagnesium interference by proper adjustment of the tinuouscountercurrent mixer-settler operation, 350 mls. organic solventphase-to-aqueous phase ratios at the of extract from the above step werecontacted with 35 wash step. Since the aqueous phase has a greaterainity mls. of wash water. for the magnesium salt values, by utilizing alimited Strip step-In a batch simulation of a five-stage conquantity ofwater at the wash step to thereby increase the tinuous countercurrentmixer-settler operation, 300 mls. organic solvent phase-to-aqueous phaseratio, a conof washed extract from the above step were contactedcentration of magnesium salt values is obtained which is with mls. ofstrip water. sufficient to suppress the re-extraction of the lithiumAThe following table is illustrative of the composition values. of theentering and exiting streams in each of the fore- Variations in theratios of values, particularly with going steps.

TABLE I Stream analyses, wt. percent Weight ratio Process step Processstream Li Mg Fe Li/Mg Li/Fe Extraction-Organic to aqueousVolume ratio=%Adjusted bitterns 0.0725 7. 43 0.598 1/102 1/8. 25 Aqueous rainate 0.0110.209 1/19.0 Diisobutyl ketone 0 0 0, Extract 0.125 0.170 3.14 1/1361/25.1 Wash-Organic to aqueous volume ratio=10l1 Extract 0.125 0.1703.14. 1/1,36 1/25.1 Washed extract 0.095 0. 002 1. 43 47/1 l/15.0 Washwater 0 0 0 Wash1iqu0r 0. 209 1. 04 9.65 5.0 1/4s.1 Strip-Organic t0aqueous volume ratio=5/1 Washed extract 0.095 0. 002 1.43 47/1 1/15.0Stripped extract.- 0. 0005 0.00014 l Strip water 0 0 0 strip liquor 0.371 0. 002 5.41 185/1 1/14.0

reference to lithium and magnesium value ratios, obtained EXAMPLE II bythe practice of the process of this invention, can be controlled bychanging the concentration of either the metallic salt or the acid, orboth. In this connection, the following 'generalizations can be made (1)increasing Extraction step-3000 mls. of an actual bitterns (a saturatedaqueous chloride solution containing about 0.182% Li, 8.65% Mg, 0.17%Na, 0.085% K, 3.03% $04-, and trace amounts of impurities) were adjustedthe metallic salt concentration at constant acid concentrawith 372 mls.of 42 B. FeCl3 solution and 20 mls. of

% HC1 solution, thereby forming soluble lithium tetrahaloferrate. Theadjusted bitterns had a gm.ion ratio of Li to Fe of about 1 to 1, and anHC1 concentration of about 0.12% to prevent hydrolysis of FeCl3. In abatch simulation of a seven-stage continuous countercurrentmixer-settler operation, 90 mls. of adjusted bitterns were contactedwith 135 mls. of diisobutyl ketone. 3, 2.5, 2 and 1.5 mls. of 42 B.FeCl3 solution were added to the aqueous phase leaving stages 7, 6, 5and 4, respectively.

Wash step-In a batch simulation of a four-stage continuouscountercurrent mixer-settler operation, 150 mls. of extract from theabove step were contacted with l5 mls. of water.

Strip step-In a batch simulation of a four-stage continuouscountercurrent mixer-settler operation, 150 mls. of washed extract fromthe above step were contacted with mls. of water.

8 EXAMPLE 1V Iron recovery process Extraction step-1500 mls. of asynthetic strip liquor, (an aqueous chloride solution containing about0.410% Li and 3.84% Fe) was adjusted with about 263 gms. of NaCl to givean adjusted strip liquor about 3 M in NaCl. In a batch simulation of asix-stage continuous countercurrent mixer-settler operation, mls. ofadjusted strip liquor were contacted with mls. of solvent comprised of32 parts tri-n-butyl phosphate, 18 parts di-2-ethy1- hexyl phosphoricacid, and 50 parts of benzene, by volume.

Strip step-In a batch simulation of a four-stage continuouscountercurrent mixer-settler operation, 60 mls. of the solvent extractfrom the above step were contacted with 20 mls. of water. Illustrativestream analyses are given in the following table.

TABLE IV Stream analyses,

wt. percent Weight ratio, Process step Process stream Li Fe Li/FeExtraction-Organic to aqueous volume ratio =1.25/1 Adjusted strip liquor0. 354 3. 32 1/0.4 0.31)(5) 0. Ol 36/1 0. 024 2. e4 "'i'/iiStrip-Organic to aqueous volume ratio=3/l do 0.024 2. 64 1/110 Strippedsolvent. 0. 0005 0. 91 Strip Water. 0 Strip recycle 0. 063 5.11 1/81 1Tri-n-butyl phosphate plus di-2fethylhexyl phosphoric acid 1n benzene.

Illustrative stream analyses are presented in the following table.

What is claimed is: 1. A process for recovering lithium values fromliquid TABLE II Stream analyses, wt. percent Weight ratio Process stepProcess stream Li Mg Fe Na K Li/Mg Li/Fe Na/Mg K/Mg Exiltion-Organie toaqueous volume ratio Adjusted .bitterns 0.160 7. 60 1. 34 0. 155 1/47. 516.1 1/49. 0 1/103 Wash-Organic to aqueous volume ratio=10/1 Wash \vaterWash liquor Strip-Organic to aqueous volume ratio=5/1 EXAMPLE IIIExtraction step-3000 mls. of an actual bitterns (a saturated aqueouschloride solution containing about 0.0854% Li, 7.28% Mg, 0.53% Na, 0.78%K, 3% S04, and small amounts of impurities) were adjusted with 143 mls.of 42 B. FeCl3 solution and 34 mls. of concentrated HC1 solution,thereby forming soluble lithiumtetrahaloferrate. The adjusted bitternshad a gm.ion ratio of Li to Fe of about 1 to l, and an HC1 concentrationof about 0.06% to prevent hydrolysis of FeCl3. In a batch simulation ofa seven-stage continuous countercurrent mixer-settler operation, 120mls. of adjusted bitterns were contacted with 120 mls. of diisobutylketone. 2, 1.6, 1.3, and 1.0 mls. of 42 B. FeCl3 solution were added tothe aqueous phases leaving stages 7, 6, 5 and 4, respectively. Inaddition, 0.1 ml. of concentrated HC1 solution was added to the aqueousphases leaving stages 5 and 4. Illustrative stream analyses arepresented in the following table.

obtained from brines or sea water, said liquid resulting from initiallyremoving the major content of sodium chloride and reducing the contentof other salts in said brines or sea water, comprising adding a chlorideor bromide of a metal selected from the group of ferrie iron, cobalt andnickel to said liquid under acidic conditions to inhibit hydrolyzationof the said metal chloride or bromide, allowing the said metal chlorideor bromide to react with the lithium ion present in said liquid to forma soluble compound containing said lithium, extracting said solublecompound containing said lithium by means of a substantiallywater-insoluble organic solvent in which said soluble compoundcontaining said lithium is soluble, and recovering the lithium values,in the form of lithium chloride or bromide, from said organic solventextract containing the soluble compound containing said lithium.

2. A process as claimed in claim 1, wherein hydrolyzation of the metalchloride or bromide is inhibited by the addition of a chlorineorbromine-containing acid.

TABLE III Stream analyses, wt. percent Weight ratio Process step ProcessStream Li Mg Na K Fe Li/Mg Na/Mg K/Mg Li/Fe Extraction-Organic toaqueous volume ratio Adjusted bitterns 0.0805 6. 86 0. 50 0. 74 0. 6631/85 1/13. 7 1/0. 3 1/8. 23 =1/1 Aqueous railinate. 0. 042 0. 082 1/2Diisobutyl ketone O 0 0 0 Extract 0. 004 0. 020 0.22 0. 38 1. 98 2.2/17. 0/1 13. 1/11 1/31 3. A process as claimed in claim 2, wherein theorganic solvent is an oxygen-containing solvent.

4. A process as claimed in claim 2, wherein the organic solvent isdiisobutyl ketone.

S. A process as claimed in claim 2, wherein the organic solvent is amixture of diisobutyl ketone with a minor amount of tributyl phosphate.

6. A process as claimed in claim 2, wherein the metal chloride is ferriechloride.

7. A process as claimed in claim 6 wherein hydrolazation of the ferricchloride is inhibited by addition of hydrochloric or perchloric acid.

8. A process for recovering lithium values from a liquid obtained frombrines or sea water, said liquid resulting from initially removing themajor content of sodium chloride and reducing the content of other saltsin said brines or sea water, comprising adding ferric halide selectedfrom the group of ferrie chloride and ferrie bromide to said liquidunder acidic conditions to inhibit hydrolyzation of the ferric halide,allowing said ferrie halide to react with the lithium present in saidliquid to form soluble lithium tetrahaloferrate, adding a substantiallywater-insoluble oxygen-containing organic solvent to the liquid toextract the lithium tetrahaloferrate therefrom, separating the organicsolvent from the liquid and adding water to the solvent to extract thelithium tetrahaloferrate therefrom, adding sodium or potassium chlorideto the water extract to increase the chloride ion concentration thereof,adding a ferrie-ion Aselective organic solvent to the water extract torecover said ferrc halide therefrom, separating said ferrie-ionselective organic solvent solution from the water extract, adding waterto the solvent to extract said ferrie halide therefrom, and recoveringthe lithium values as lithium chloride or bromide from the water extractcontaining the same.

9. A process as claimed in claim 8, wherein the ferric chloride is aferric chloride hydrate.

10. A process as claimed in claim 8, wherein the oxygen-containingorganic solvent is a substantially waterinsoluble alcohol, ether, esteror ketone.

11. A process as claimed in claim 8, wherein the ferric halide isrecycled in the process.

12. A process as claimed in claim 8, wherein a chlorineorbromine-containing acid is added to the liquid to inhibit hydrolyzationof the ferrie halide.

13. A process as claimed in 12, wherein the acid is hydrochloric orperchloric acid.

14. A process as claimed in claim 8, wherein the ferricion selectiveorganic solvent is a mixed solvent comprising a neutral phosphorusester, an acidic phosphorus ester and a non-polar aromatic hydrocarbondiluent.

15. A process as claimed in claim 14, wherein the mixed solventcomprises a mixture of tributyl phosphate and di(2ethyl hexy1)phosphoricacid in benzene.

16. A process for recovering lithium values from waste liquids resultingfrom the processing of brines or sea water, comprising adding a solublecomplex-forming metal chloride or bromide selected from the group offerrie iron, cobalt and nickel to said waste liquid under acidicconditions to inhibit hydrolysis of said chloride or brofide, allowingsaid added metal chloride or bromide to react 'with the lithium ion ofthe lithium salt to be recovered to form a complex therewith which issoluble, extracting said complex by means of a substantiallywaterinsoluble organic solvent in which said complex is soluble, andrecovering the lithium values, in the form of lithium chloride orbromide, from said organic solvent extract containing said complex.

17. A process as claimed in claim 16, in which the organic solvent is amixture of diisobutyl ketone with a minor amount of tributyl phosphate.

References Cited UNITED STATES PATENTS 2,564,241 8/ 1951 Warf 23-32 X2,808,313 10/ 1957 Fleischmann 23--32 3,144,304 8/ 1964 Nagumo et al23-140 3,154,500 10/1964 Jansen et al. 3,306,712 2/ 1967 Goodenough etal. 23--89 X OTHER REFERENCES Clark: Nucl. Sci. Abstr. Vol. 16, No. 11,Abstr, No. 13128, June 12, 1962.

OSCAR R. VERTIZ, Primary Examiner G. T. OZA-K, Assistant Examiner U.S.Cl. XR.

